SQL joins are one of those concepts everyone nods along to but few can confidently draw from memory. This tool computes real join results from your own sample data, live, alongside a Venn diagram of which rows each join type keeps.
What Is the SQL Join Visualizer?
Edit two small CSV-style sample tables, pick a join type, and see the actual computed result set — not a static diagram, but real join logic running against your data — plus a Venn diagram that visually emphasizes which region of the two tables that join type keeps.
How to Use It
- Open the tool at /tools/sql-join-visualizer.
- Edit the sample “users” and “orders” tables (or leave the defaults).
- Click through INNER, LEFT, RIGHT, FULL OUTER, and CROSS join buttons.
- Watch the result table and Venn diagram update instantly.
Key Features
- Real computed joins, not static illustrations — edit the data and the results update live.
- Five join types: INNER, LEFT, RIGHT, FULL OUTER, CROSS.
- Venn diagram visually showing which table regions each join keeps.
- Generated SQL syntax shown alongside the result.
When to Use This Tool
- Learning or teaching SQL joins with a hands-on, editable example.
- Debugging unexpected join results by testing similar data shapes to your real tables.
- Quickly reminding yourself of the difference between LEFT and RIGHT JOIN before writing a query.
Try It Now
Open SQL Join Visualizer directly, or press ⌘K and type the tool name from anywhere on the site.
Part of the SQL Tools collection on WebdevToolbox — free, browser-based developer tools with no login required.